Transformer



Jan. 8, 1929. 1,698,608

R. S. PIPER TRANSFORMER Filed April 5, 1925 2 Sheets-Sheet 1 Jan. 8, 1929.

R. s. PIPER Y TRANSFORMER Filed April 5, 1925 2 Sheets-Sheet 2 7/134 Z MMGHM Patented Jan. 8, 1929.

UNITED STATES RALPH S. PIPER, OF CHICAGO, ILLINOIS.

TRANSFORMER.

Application filed April 3, 1925. Serial No. 20,510.

Radio apparatus of all kinds has recently been subjected to critical structural examination with a view to effect more complete and more accurate transmiisions. During the early period of development, radio inrestigations were confined mostly to circuit relations and the perfecting of the three electrode tube These latter details have been worked out. if not to final form. at least sufficiently wel to give reliable and efficient results, and to require corresponding improvements in the structural design of the several elements of a radio circuit.

My invention relates to improvements in the mounting of a transformer, especially adaptable to use as a coupler element be ween the several stages of a radio frequency amplification system, although these improvements are applicable also in power circuit work to transformers, inductances, and induction coils.

One object of my invention is to do away with large masses of di-electrics as supportingparts for the operative parts of electrical apparatus.

Another object is to permit the use of very light operative parts and yet insure that such parts maintaintheir relative alignments.

Another object is to free inductive elements from local capacity effects, and to reduce leakage and di-electric absorption losses. Other objects will appear as the description of my invention is given in connection with the accompanying drawings, which constitute part of this specification.

Fig. 1 is a longitudinalelevation, part sectional, of a transformer which embodies my invention.

Fig. 2 is a ititossscctional view on the line 1-1 of Fig. 1.

Fig. 3 is a 'ierspective view of a transformer of my invention.

Fig. l is a side elevation of a modification of my improved transformer.

Fig. 5 is a plan view of the transformer shown in Fig. 4, normal to its principal axis.

Fig. 6 is a side view of a modified detail of the parts shown in F ig. 5.

Various expedients have been proposed to render coils used in radio apparatus self-supporting. Aside from being wasteful of space, these devices almost invariably violate the fundamental law of magnetic induction which requires wires should be closely assembled to create strong effects. with freedom from distortion. I have designed the coil structures of my invention primarily to give excellent electrical results, and have combined with such coils supporting parts that permit the coils to continue to discharge their primary functions indefinitely, with practically complete freedom from both or losses and distortion.

In my prior Patent 1,4383% of date Dec. 12. I disclosed and claimed a disposition of windings adapted to influence each other according to the best possible conditions under which magnetic induction can take place from one winding to another, and the ha provcments of this application are directed to utilize the principles of the patent referred to as applied to coils which operate without being impeded in their action by the harmful effects of (ii-electric masses, used as supports for the windings.

In the drawings like reference characters are used on the several views to indicate the same parts.

Referring to Fig. 3, I have shown therein the general assemblage of coils structure and supporting parts. In this figure 8 is a. cylindrical coil of very line copper wire, the turns ofwhich extend between a series of bosses integral with side rings 1. The bosses 4 serve as sockets for rods 3 which confine the coil 8 circumfercntially. see Fig. 2. The rods 3 are carried eccentric-ally in the bosses 4, so as to provide considerable flat surface for the edge of the coil 8 to impinge upon. It will be noted, however, that there exists only a line contact between the coil and its supports. The material of the supports is insulating, preferably bakelite. The rings 1 which ca rry the bosses 1 constitute the skeleton upon which the operative coils are hung, and it will be apparent that these rings not only act as sturdy supports, but are so located that they are well. out of the magnetic and electrical fields set up by the coils when in action. and hence energy losses and distortions are avoided.

As shown in Figs. 1 and 2, coil 7 has only a fraction of the number of turns of coil 8, both coils being single layer wound. Using coil 8 as a primary it will be free to set up as nearly perfect a cylindrical field as if it were a solenoid, and as such fields are known to be most uniform at their extreme ends, the device will act with great perfection as a coupler between tube circuits with tuned radio frequency stage circuits, and I have found it to give very exceptional results in such an application. Part of this success is due to the character of the coupling between the coils, as explained in my earher patent. It may be particularly pointed out here, however, that the effect of the alternate very close and very open coupling between the sections of windings 7' in which the supporting rings 1 are connected by two T shaped bars, which are moulded in tegra'lly with the rings. These bars 10 maybe solid T barsbut- I prefer to fashion them with a number of oblong apertures 12 which operate to cut down absor tion losses and leave the bars practically as strong as it solid. Each bar presents a thin straight edge portion towards the axis 01: the rings and these edges may be rounded. 'lhese bars act sim' the rods 3 or l and 2 to hold "f with its axis in the axis of the rings 1.

Besides the two integral bars 10 the rings 1 are turt-he' connected together by a removable bar 14:, also having a general T shape. This bar 14 is provided with end plates 18, see Fig. 5, whichmay be riveted to the rings 1 by rivets-13. The removable bar 14. provides a ready means for assembling the coil in its supporting unit, and allows ct its manufacture as a unit by itself. Fig. 6 shows a modification of the removable bar showing slots 16,

cut by a milling cutter after the bar is moulded. size to the slot to enable it to take the ring 1 moderately tight. In this form the rings 1 may be cemented in place.

The bar it carries a lug 17 which is slotted to receive a bracket 9. This bracket has a screw hole'19 directly under the center C of the coil 8. By reason of this relation the coil may be initially adjusted with respect to its mates in the successive sta es or" amplification to effect a cancellation oi stray fields, after which the bracket maybe fixed in position through hole 20.

it will be seen from the above description of coils and their supporting parts that the coils are not only held in the exact position desired,

but they are well protected from accidental injury.

What I claim as my invention is 1. in a radio transformer, a coil and a dielectric support therefor comprising a frame made up of aper'turcd end members, connected together by tie bars provided with end lugs, said tie bars engaging the external surface of the coil by line contact, and said lugs spacing the coil from the end members of the frame also by line contact with the coil.

2. A radio frequency transformer, comprising a coil structure, a supporting frame for said coil engaging the coil at exterior surface points on the coil, and fixation means for said frame designed to permit the coilto be adjusted and fixed in various positions around a line passing through its center of figure.

RALPH S. PIPER.

The cutter ives the arecise contour and 

